What Is Dyslexia?
Dyslexia is a chronic problem with reading. It is a common learning difficulty, affecting a large percentage of those identified as "learning disabled." According to the National Institutes of Health, up to 15% of the U.S. population has significant difficulty learning to read. People with a learning difference like dyslexia may have trouble with reading, writing, spelling, math, and sometimes, music. Three times as many boys as girls have dyslexia.
Most people think dyslexia is a condition that involves reading from right to left and reversing words and letters. While some people with dyslexia do have these problems, they are not the most common or most important characteristics of dyslexia. Experts say dyslexia has little to do with recognizing the visual form of words; rather, the brains of people with dyslexia are wired differently. This difference makes it difficult to break the letters of written words into the distinct sounds (or phonemes) of their language, a capability called phonological awareness.
Dyslexia can occur at any level of intellectual ability. Sometimes children with dyslexia appear to their teachers and parents to lack motivation or not to be trying hard enough. Dyslexia may be accompanied by -- but is not a result of -- lack of motivation, emotional or behavioral problems, and sensory impairment.
A more positive view of dyslexia describes people with dyslexia as visual, multidimensional thinkers who are intuitive, highly creative, and excel at hands-on learning. Many people with dyslexia shine in the arts, creativity, design, computing, and lateral thinking.
What Causes Dyslexia?
Dyslexia tends to run in families, and researchers have identified the genes that may be responsible for the condition.
Scientists have also found specific brain differences involved in dyslexia. Brain images show that dyslexia results from certain structural differences in the brain, particularly in the left hemisphere.
Brains of people with dyslexia show very little activity in areas known to be highly important in linking the written form of words with their phonetic components. So in order to read, people with dyslexia must develop alternative neurological pathways. They compensate by making more use of a front-brain section called Broca's area, traditionally associated with other aspects of language processing and speech.